A case of autosomal dominant polycystic kidney disease with systemic lupus erythematosus developing after SARS-CoV-2 vaccination.

Although SARS-CoV-2 vaccines, particularly mRNA-based formulations, have demonstrated high efficacy and safety, adverse events including autoimmune activity have been reported. We report a case of systemic lupus erythematosus (SLE) following SARS-CoV-2 vaccination in a 52-year-old Japanese female with autosomal dominant polycystic kidney disease (ADPKD). The patient presented with nephrotic syndrome and severe thrombocytopenia and fulfilled the following four criteria for SLE classification: positive antinuclear antibodies, positive anti-ds-DNA antibodies, renal involvement, and reductions in two blood cell lines (leukopenia and thrombocytopenia). The patient responded favorably to prednisolone therapy, although hydroxychloroquine was avoided because of a suspected allergic predisposition. This case underscores the potential for exogenous triggers such as vaccination to induce SLE, highlighting the need for vigilance in managing autoimmune responses, particularly in patients with chronic conditions such as ADPKD. Despite the patient's history of ADPKD, no previous reports have linked this condition to post-vaccine SLE. Concurrent nephrotic syndrome in patients with ADPKD is rare, and the possibility of other treatable glomerular diseases should be considered when this is seen.